Arafat died of some kind of fairly rapid onset blood disorder, according to this Guardian story: http://www.guardian.co.uk/israel/Story/0,2763,1374609,00.html "He looked like a bird, because he had shrunk," she says. "His face was as if he had been burned by the sun. It was red, red, red, and his skin was peeling." "But French physicians - and specialists in toxicology and biological warfare - had made little progress in determining the cause of his illness. After four days of tests, they were confident that he did not suffer from leukaemia, but they had been unable to locate the cause of the blood disorder."
U.S. says working on initiative to de-escalate Syria fighting, with focus on Aleppo (Reuters)
from the article: Russian-born businessman: I met poisoned ex-spy Litvinenko in Israel